GET THIS SINFUL BEING OUTTA HERE
by Puppet String
Summary: The summer is over. Dipper and Mabel go back home to begin high school. As though that isn't bad enough, Bill has taken the liberty of moving in under the ruse of an exchange student solely for the purpose of ruining his mortal enemy's high school experience. Mabel is having none of that, and makes it her mission to destroy Cipher's self-image. Lots of swearing. Crackfic.
1. Some Asshole Moves In

The summer was over and it was time for Dipper and Mabel to leave Gravity Falls behind, at least for the time being. With some luck, they might be able to convince their parents to let them go back for a visit around Thanksgiving, or maybe for Winter Break. Spending Hanukkah with their Gruncles would definitely be a blast. The twins were sad to leave. They'd had such fun adventures there. Now, they were going to start their first year of High School. For many, that sounded like an adventure, but after what the two of them had faced, it was just a drag.

As they said their tearful goodbyes to their new friends and to their Gruncles, Dipper couldn't shake a bad feeling. Something was wrong. He couldn't place his finger on it, but something was definitely ominous about the ride home. Like they were being watched.

"Mabel, do you feel that?"

"What?"

"Like we're being watched."

"We're on a bus, Dipper! There's nothing to do but people watch. I'm sure it's nothing to worry about- just some of these friendly bus travelers trying to pass the time."

"If you say so..."

The bus ride took forever and by the end of it, Dipper felt sick with worry. Mabel's words hadn't soothed him. Not to mention Waddles had been agitated the whole trip. Pigs had good senses! Dipper was now positive something terrible had followed them back from Gravity Falls.

"Welcome home, kids! How was your summer?"

Their parents rushed forward to greet them with a warm hug.

"It was great, Mom!" Mabel chimed jovially, "I got a pig- his name's Waddles- and we had so much fun with Soos and Wendy and Gruncle Stan and Gruncle Ford and Candy and Grenda and-"

"Whoa, there, Mabel! Tell us about it over dinner. We whipped up a special welcome home spread!"

"Hooray!" Mabel grabbed Dipper's arm and pulled him inside. "C'mon, brobro, let's eat!"

Dipper just pushed his food around with a fork all night. Something was off. Unfortunately, his father noticed.

"What's wrong, son? I'd expect you to be starving like your sister."

"What? Oh, no, I'm fine, Dad. Just a little sick from the bus ride. I just need some fresh air."

"Give the rest of your food to Mabel's pig, and put a jacket on before you go out."

"Yep."

Outside, it was cold and loud. Cars drove by, the neighbor's dog was barking incessantly, and Dipper could still hear Mabel through the sliding glass door that led to their yard, yapping about the summer. He should be with her, sharing in the excitement, but he just felt so terrible. Why did he feel so terrible? The summer had been great. Was it like anti-homesickness? Did he miss Gravity Falls more than he wanted to be home? No, that wasn't it. He knew he'd readjust quickly, and that he'd be able to see his Gravity Falls friends soon enough. So what was the big idea?

Dipper gave up trying to figure out what was wrong, wrote it off as puberty, and went to bed. Mabel was already there, laying in her top bunk and scribbling with crayons in a notebook.

"Dipper, look! I drew a picture of Waddles eating Gruncle Stan's favorite slipper. Remember that?"

"That's great, Mabel." Dipper wasn't really looking at the drawing.

"You look sick, Dip. Maybe we should hit the hay, huh?"

"Yeah."

Mabel turned off the light, snuggling closer to her stuffed animals.

"Night, Dipper."

"Night, Mabel."

Dipper's mind ventured to ungodly places that night, depicting images of their worst encounters in Gravity Falls until finally all that remained was Bill's mad cackling over a dark landscape. As the moon rose over the land, a lake was revealed, the moonlight reflecting on the tips of the waves and spelling out, "YOU THOUGHT YOU WERE RID OF ME" over and over.

Dipper woke up screaming. Mabel had to climb down and calm him. He didn't sleep again.

The next morning, Mabel followed Dipper out to breakfast, helping him to avoid tripping over obstacles in his sleep-deprived, zombie-like state. She'd have to sneak him some Mabel Juice.

"Kids, we have a great surprise for you! We're getting an exchange student. He'll be staying with us and going to your school!"

Mabel forgot all about the juice. "Really?" She squealed excitedly, "What's his name? How old is he? Is he single? Oh my gosh oh my gosh oh my gosh!"

"Kids, I'd like for you two to meet Billy! He'll be a senior this year. Isn't it great?"

The twins' jaws dropped. Their parents had invited sin into their household. Mabel hissed.

"Mom we have to get rid of him right now immediately."

"Mabel, I'm surprised at you! Don't be rude- poor Billy just got here, and you're already being mean?"

"But he-"

"No buts, Dipper! That goes for you, too, Mabel. Treat our guest with respect. It's only until summer."

Dipper died a little inside. Their guest room was going to be occupied by a demon with greasy yellow hair, a plaid track jacket, a tee shirt with a bowtie printed on it, and a shitty little tophat barrette clipped to one side of his head.

' _Bill Cipher dresses like a fucking train wreck. He clearly doesn't know how to behave in the human world. How did he acquire a physical human form? What poor fool is he using as a puppet? I must help them before their high school life is destroyed.'_ Dipper would try and contact the body's spirit later. For now, they had to go back to school shopping.


	2. A Miserable Shopping Trip

Office Hut had isles upon isles of miscellaneous supplies. Everything from notebooks to backpacks to pens and desk snacks- it was like a boring businessman's dream. Dipper and Mable stood in the entrance with their parents and Bill.

"Alright, kids. Your father and I need to run up the street to Grocery Town to grab some ingredients for dinner. We'll swing by and get you in forty minutes or so. Try and be done shopping by then! Billy's volunteered to watch you two, so stick with him."

"Awe, what?" Dipper protested, "We don't need to be babysat while we buy pencils!"

"Well, then, Billy's job will be easy. See you soon!"

The twins wrinkled their noses. Fuck this guy! Who gave him the right to follow them around incessantly like a dark cloud? What did he even know about school? Nothing, probably. He didn't even seem to know how to take care of his flesh vehicle. He'd been in more accidents in one day than Dipper or Mabel got in to in a month! He was covered in bandages and bruises, and he desperately needed a shower. He was repulsive.

"Leave us alone, Bill! We can shop without you." Mabel grabbed Dipper's wrist. "C'mon, Dipper. Bill can find his own supplies."

"Wait, what?" Bill looked surprised.

"You'll need supplies to be a senior, you know." Mabel tapped her foot. "I thought you were like omnipotent or something!"

"Shut up! I am. I just like bothering you two, is all. You ruined my plans so now I'm going to ruin your lives."

"Not if we can help it." Dipper glanced at Mabel, pointing off in the direction of the far wall. "He can't hover around both of us!"

Mabel nodded. "One, two, three, GO!"

They sprinted off in opposite directions, leaving Bill standing awkwardly at the front and whipping his head back and forth, trying to figure out which twin to follow. He'd already lost sight of Dipper, so he decided he'd just catch up to Mabel and belittle all the stupid things she grabbed for her basket. He took off after her, cursing his weak mortal form as he clipped the edges of shelves, accumulating new wounds.

He finally caught up to her by the backpacks. She was admiring a pastel pink and green bag, rubbing her chin as she tried to picture how it would look if she added glitter and patches to make it cooler.

"What a stupid color," Bill sneered, "Looks like strawberry milkshake and toothpaste."

Mabel grinned. "Strawberries! I could put glittery strawberries on the front! Thanks, Bill- I'll get this one!"

Bill slapped his forehead. He'd inspired her? What a little shit! Time to kick it up a notch.

Next isle was notebooks. Mabel selected four- one with a unicorn on the front, one depicting her favorite boy band, one with multicolored stars, and a solid blue glitter notebook.

"Sheesh, kid! Those are the ugliest notebooks I've ever seen. They're almost as bad as your sweaters!"

That struck a nerve. He watched gleefully as Mabel looked up at him, hurt in her eyes. Tears welled in the corners.

"You really think my sweaters are ugly?" She whimpered.

"They're the worst! You have the most awful sense of fashion of anyone I'v ever seen, and I've been around! You'd be better off fishing clothes out of the trash, you pathetic little-"

"Hey! Leave that poor little girl alone, you bully!"

"Yeah! Who gave you the right to criticize her? I think she's wearing a lovely sweater."

"It's the cutest sweater I've ever seen. Besides, at least she knows how to shower. News flash, buddy- I can smell you from here!"

"Yeah! Have you ever heard of soap? Get a life, asshole. Oh, and that jacket with that hat? You've got no right to talk shit when it comes to fashion, honey."

Mabel turned to the other customers, smiling and wiping the tears from her face. "Thanks, everyone." She choked.

"No problem, Kid. You want me to get a manager to throw that jerk outta here for ya?"

"No, no- it's okay. I'll be fine."

He was ashamed. Did mere humans really think he looked like a dirty, powerless bum?

The other shoppers slowly returned to examining pens and computer chairs while Bill followed Mabel to the far corner of the store, where they stood alone. Mabel whipped around, tears completely gone and a murderous look in her eye.

"Listen here you geometric one-eyed piece of shit with no depth perception, I know how to play heart strings. I can take your constant belittling and bully-like behaviors and turn everyone around me against you. I'm fucking adorable and I can guarantee that no matter who we're with, they'll take _my_ side. That being said, I'm fine with you picking on me, if you piss me off, I'll just throw you to the crowds to be ripped apart. But let me warn you: if you try anything on Dipper, I will obliterate you. Any trace of your pathetic existence will be ground to dust and scattered to the winds. You're human now. Weak. Vulnerable. Mortal. Don't test me, Cipher. I can be your best friend, or the thing that makes you want to stop existing. It all depends on how you treat my brother. Capiche?"

Bill started at her in shock. Mabel _swore_ at him? Mabel _threatened_ him? How dare she? Didn't she know what he was? An all-powerful dream demon, that's what! He narrowd his eyes to slits and wrinkled his nose in disgust.

"Don't ever talk like that to me again, kid. You can't touch me. I'm-"

"Bop." Mabel jumped up and booped him on the face. "I can."

"I'm serious. You and your brother are going to be the two most miserable kids on the face of the Earth until I make sure you can't take it anymore! I'm gonna-

Mabel grabbed the front of his shirt and yanked him down, causing him to lose balance and fall right in to the corner of the metal discount basket face-first.

Pain was getting less and less hilarious.

"Whoops." Mabel flipped her hair and walked off toward binders.

The twins finished shopping just as their parents arrived and met up by the checkstand.

"Hi, kids! How was it?"

"Fine."

"Great!"

"Find everything you need for school?"

"Yep! And they even had an awesome sale on crayons!"

"Good for you, Mabel! I can't wait to put your pretty pictures on the fridge. Did you get some for Dipper, too?"

"Of course! I'd never forget my brobro."

The twins high-fived.

"Oh, Mabel, that reminds me- there were some 3d stickers on sale. I grabbed you the last sheet of them."

"Thanks, Dipper! I can stick them to my binder!" Mabel hugged her brother. The hostile, menacing beast from earlier was nowhere to be found. Bill began to wonder if he'd hallucinated it.

' _I'm gonna have to keep an eye on her,_ ' He thought as he sat awkwardly between them on the ride home.

Dipper noticed Bill watching Mabel, making a mental note to keep an eye out for his poor sister.


	3. SCREAMING CHILDREN ON BURNING DEATH BUS

"Wakin' wakin' eggs and bacon!" Mabel shook her brother awake. She was already dressed- she wore the sweater with her name on it that lit up. She always did that on the first day of school so people would know her name and (hopefully) feel more inclined to address her and start a conversation.

"Mabel, it's six thirty in the morning! What do you-"

"FIRST DAY OF SCHOOL!"

"Oh. Right. Yeah, I'll meet you in the kitchen after I get dressed."

Mabel skipped out of the room, then paused. Was Bill awake? She peeked into the kitchen. Nope. A wicked smile spread across her lips. She grabbed a match from the cupboard. Carefully, she crept past her parents' room. They were still getting ready. She could hear her father humming in the shower and her mother cursing at the mascara for getting in her eye. As she got closer to Bill's door, she was thrilled to hear him still snoring.

Perfect.

Mabel carefully maneuvered her way to the clock on Bill's nightstand and reached over to turn it off.

Her heart skipped a beat as he rolled over, but he didn't wake up. What an idiot. She slipped the match into the lining of Bill's hat barrette. She turned the old-style bell alarm over and looked carefully at it. It wasn't even set to begin with! Her work with it had been meaningless! Abort mission, abort mission!

She headed for the door.

"Mabel?"

Dipper's voice scared her half to death. He was peeking through the door.

"What are you-"

She shoved a hand over her brother's mouth and raced out of the room, closing the door most of the way behind her.

"His alarm isn't set," She whispered excitedly.

"Oh. I guess we'd better wake him up so he-"

"NO. Let's make him late!"

"Mabel, that could make _us_ late."

"Not if we leave without him."

Dipper thought for a moment.

"I'm in."

The twins sat down and finished their breakfast with time to spare.

7:25am. Five minutes until the bus would be there and they could ditch Bill.

"Kids?"

Their parents, coming to kiss them goodbye.

"In the kitchen, Mom!"

"Oh, the three of you will-" their mother looked surprised. "Where's Bill?"

"Still getting ready, I guess," Dipper announced sweatily.

Their mother narrowed her eyes. "Have you seen him out of his room this morning?"

"No," The twins confessed.

"Dipper, go wake him."

"What? Why do I have to-"

" _Now_ , mister."

Dipper grumbled as he tossed open Bill's door and turned on the light. The rudest method he could think of to wake the gross demon up.

"Rise and shine, the bus will be here in three minutes."

Bill sat up.

"I thought humans were supposed to get eight hours of sleep? It's only been three!"

"Your bedtime isn't our problem. If you aren't ready, we're leaving without you."

"I'm ready, I'm ready!" Bill threw off the sheets to reveal he'd slept in his clothes. He smelled like something had crawled in bed with him and died. His greasy hair was a wreck and his teeth were coated in plaque.

"Whatever you say, Bill."

The demon grabbed his hat barrette and headed out the door with the twins to wait for the bus.

"Ow, stop it!"

Bill was pulling at Mabel's hair.

"Make me."

"Leave her be, Bill."

"Not on your life, shortstop!"

Bill grabbed Dipper's hat and held it above his head.

"Jump for it!"

"Bill, give it back!"

"You gotta take it from me, kid!"

He tanked on Mabel's hair. She saw the opportunity and took it. She "fell" back at full force, yelping as she aimed her elbow at Bill's exposed diaphragm and hit him hard. He doubled over and gagged, desperately trying to catch his breath. She'd knocked the wind out of him. He dropped the hat as Mabel rubbed her head.

"Serves you right for picking on her," Dipper muttered as he retrieved his hat from the sidewalk. Bill shot Mabel a dirty look. He knew that there was no way that was an accident.

The twins had agreed to sit one seat apart so Bill couldn't torture both of them from behind. They sat in the middle of the bus on the right set of seats, each by the window. Dipper was in front of Mabel and Bill sat with her, hoping to be as much of a nuisance as possible to them.

Mabel shrunk away from Bill's stench. He still obviously hadn't changed clothes, showered, or brushed his teeth. His first day was going to be Hell.

"Stop hitting yourself!"

"Bill-OW- Stop-OW-leave my a-OW! Leave my arm alone!"

Bill was tormenting Dipper.

"Bill, I'm warning you," Mabel hissed with her sleeve over her nose.

He shot her a defiant look and went back to pestering her brother.

Mabel reached into her bag and spritzed him with some flowery-scented hairspray, much to the relief of those forced to sit nearby. Next, she pulled out her happy-faced stone and a little steel action figure she'd found in the woods over the summer and started attempting to pull Bill off Dipper.

"Leave my brother alone!"

"Get off me!"

Bill turned around, blocking everyone else's view, and Mabel brought her toys together and made a spark that set the hairspray-coated beast ablaze with a _FFFWWP_ sound.

Bill screeched in agony as the fire charred his flesh and burnt through a patch of his hair.

Mabel's rock was actually a piece of flint with googly eyes. She'd found out how to make sparks one day when she made the steel soldier kiss it and had started a small fire in the yard by the Shack. Luckily, Soos had been there to put it out. Now, however, Soos wasn't there to help Bill.

Mabel hopped over the seat and grabbed her brother as the bus screeched to a halt and all the kids ran off, wailing in terror.

The interview with the principal was quick. Mabel had whipped up some tears and even let the fire burn her cheek a little bit to make it more convincing.

"What happened on the bus today, Miss Pines?"

"I d-dunno," Mabel sobbed, holding some ice to her cheek. "One minute, I w-was trying to get Bill to l-leave Dipper alone, the next, he was on fire and everyone was screaming and I-I-" She cried as hard as she could.

"Any idea how he could have caught?"

"Nuh-uh." She whimpered. She'd chucked the rock in all the confusion, so there was nothing to link her to the crime. What would a little steel doll prove in a soon-to-be-thirteen year old's bag? Nothing.

"Very well," The principal sighed, "You can go for now. Come back and visit the nurse if you need any more ice."

Mabel kept the ice clutched close, giving Bill a dirty look as she passed. His turn for the interview.

By the end of the day, she hadn't been called back and Bill hadn't appeared in any of his classes, so it was pretty safe to assume Mabel was off scott free. The match she'd planted in his hat probably hadn't hurt anything, either.

She and Dipper met her parents in the car, pleased to see a charred, partially-bald Bill waiting for them with his arms crossed in the back seat. Mabel inhaled deeply. She couldn't tell what smelled better- the scent of Bill's charred flesh, or the sweet scent of victory.


	4. Everyone's precious cinnamon roll, Mabel

Heads up, things get pretty intense in this chapter.

You have been warned.

* * *

The twins' parents finally had the much-needed "deodorant talk" with Bill, so he took a shower before school the next day. A cold one, to help soothe his burns. Slowly, he began to realize that being a human was incredibly shitty.

Mabel had been "kind" enough to wash Bill's clothes with her own laundry the day before, making sure to rub the inside of his shirt and socks in the grass outside once they were dry. That special kind of grass that gets in your clothes and stabs you all day until you puck every last particulate out of it. Good luck, Cipher.

Bill sat scratching himself on the bus, wincing every time his hand touched a burn. Ow. Ow. Ow.

Mabel grinned. He wouldn't make it through the first semester. She'd make sure of it.

Three three of them had only two classes together: P.E. and Drama. The twins had picked Drama as an elective over auto shop because Dipper couldn't do the manual labor required for such a class.

As they hopped off the bus, Bill cut them off from the hall, narrowing his eye.

"See you runts in gym," he hissed.

Mabel was looking forward to it.

She and Dipper had Science together, but no other non-elective courses (aside from P.E.)

The clock ticked by too slowly. She just had to get through lunch. The last three periods of the day were with Dipper, though two of them involved being in close proximity of Bill. Oh well. She was working on that.

Finally, lunch. The twins found each other and sat together. They'd met up with a few old friends and found a vacant table on campus.

"Yeah, the summer was great! We fought actual monsters and met our other Gruncle. He had been in a parallel dimension the whole time!"

"Seriously?"

"Cool!"

"Wow. I never pegged you and Dipper as monster hunters! What was the scariest thing you faced?"

Dipper rubbed his chin, taking over the conversation.

"No contest, that was definitely-"

A backpack full of books sailed forward. Mabel knocked her brother down, taking the hit for him.

"Me, losers!" Bill had found their table.

Mabel had taken the hit on her shoulder and in the ribs. It hurt pretty bad.

' _I can work with this._ '

She didn't sit up. Instead, she lay on the ground and started crying, focusing on the pain for motivation. She knew it would bruise, at the very least. Usually,. she'd hold back tears for Dipper's sake, but her objective of getting Bill out of their lives was much more important than her bravado.

"Mabel! Are you okay?"

"Oh, poor Mabel!"

"Hey, asshole, what the hell was that for? They weren't doing anything to you! Pick on someone your own size!"

Bill leaned over grinning at the group of freshmen.

"Like who? You're all a bunch of pipsqueaks!"

"Thomas, is this asshole giving you trouble?"

Bill spun around to see a fellow senior, a 5'7 volleyball player named Lana. She had Gym with him and the twins.

"What if I am?"

She grabbed his collar and picked him up. He had no right calling anyone else a pipsqueak when he himself stood at only 5'2.

"Then we have a problem."

Lana glanced over Bill and saw Mabel crying.

"Did you do this?" She demanded, her forehead pressed to Bill's. The demon began to sweat a little. He had friends in Hell who were less intimidating.

"Y-Yeah, and I'll do it again!"

Lana hauled Bill off to the girl's bathroom, grabbing a moldy who-knew-what off the floor along the way. She shoved him into the stall and locked it behind them, then held Bill down and forced him to eat the molded floor beast.

Soon, Bill was vomiting everywhere, tears rolling down his cheeks.

"WHAT HAVE YOU DONE TO ME?" He wailed, hunched over the toilet.

"Nothing yet."

The rest of lunch was one swirly after another in a vomit-filled toilet, which Bill kept replenishing. When the bell finally rang, Lana threw him down and kicked him in the ribs.

"Tell no one, Cipher."

"I wasn't planning on it!" Bill was humiliated. He hauled himself off the floor and rinsed his head off in the sink. Being a human was the worst choice he'd made in his immortal life, and this was the worst day of his immortal life by far.

He was late to gym, and by the time he got there, Lana had told everyone about what he'd done to their sweet, precious cinnamon roll, Mabel at lunch just in time for dodge ball. By the end of class, his own team had hit him half as many times as the opposite team. He had bruises on his bruises and cuts on his cuts.

Mabel watched him sit alone in the corner in drama while everyone else played improvisation games. When school was finally over and the bus pulled up, Bill couldn't have been more ready to get out of that place. He skipped dinner, claiming (not so falsely) that he'd eaten something at lunch that wasn't agreeing with him and went straight to his room. There, he sat for hours, replaying the day over in his head until he cried himself to sleep.


	5. A CONCUSSION

Enough was enough. Bill was fed up with Mabel and he antics. This was the day she'd mark as the worst of her life; he'd make sure of it. Dipper could wait. Besides, he'd probably be upset by the sight of his sister in emotional agony.

Bill got up early that morning. He had a plot to carry out. The demon sneakily slunk around on the sly with a sinister smile plastered across his face. The door made no sound as he pushed it open, nor did the carpet beneath his feet. The twins lay in their bunks, slumbering soundly and with a false sense of safety. Bill stood on his toes and peered over the side of the top bunk's frame, making sure that Mabel hadn't been disturbed. It appeared as though luck was on his side.

His dirty, sweaty hand reached across her and toward her beloved pet pig, who was curled up next to her. His finger was only a centimeter away when a searing pain overcame him, causing him to shriek and fall back onto the carpet. Mabel sat up, silhouetted gravely by the dim illumination of the bedroom nightlight.

Blood oozed from a long cut across Bill's scalp, running down his face, blinding him. It clotted in his hair. It dripped all over his clothing and speckled the carpet. Mabel turned her head slowly to gaze in Bill's direction. Bill couldn't focus- his vision was blurred, doubled, and corrupted by the red liquid pouring down into his eyes. "Never, ever touch Waddles you loathsome, unholy, pathetic little slug." Her voice sounded more like a cross between a growl and a shriek than Bill knew was possible for a human. His heartbeat accelerated at a rapid rate and he shook, tears forming in his eyes. He was actually _afraid_ of this human.

His howl of pain had awoken Dipper, who sat dazed and staring at him. Mabel could hear their parents running up the hall. Her mother switched on the light and started inside with a wild look across her face and a hunting knife at the ready.

"Bill? What are you doing in the kids' room?" Their father demanded, a baseball bat in his fist, "And what happened to your head?"

Mabel rubbed her eyes, looking back to her usual self. "Bill tripped in the hall and hit his head on the doorway," She told them innocently, "I guess he must've been on his way to the kitchen for a midnight snack. He did skip dinner, after all."

Bill narrowed his eye, trying to stare at her menacingly through the blood. "Y-yeah. Sure."

Their mother set her knife down on the nightstand and took a look at Bill's wound. "Wow, that door frame sure did a number on you! We ought to take you to the emergency room. You might have a concussion."

The family loaded up into the car and spent the rest of the night in the hospital waiting room, flipping through magazines and dully watching late-night advertisements and dull shows.

Bill did, in fact, have a concussion. He was vomiting, had a splitting headache, trouble focusing his vision, and so on. He had to stay home until Friday.

In the meantime, the twins had a peaceful couple of days at school. During one of those days, Dipper finally asked something that had been plaguing his mind.

"Hey, Mabel?"

"Yeah?"

"The other night,w when Bill got his concussion..."

"Mmhm?"

"Did he really hid his head on the doorway? I could've sworn I heard you talking before that. Something about Waddles."

Mabel's smile faded.

"Dipper, sometimes people have to do terrible things to other people in order to keep those people from doing horrible things to the people they care about- y'know, people gotta protect their people, which sometimes involves hurting people."

"Mabel, I think you lost me there."

"Don't worry about it, brobro. All you need to know is that your sister's gonna keep you safe!"

"Okay then?"

"Anyway, about the homework..."

Friday rolled around and Bill showed up a hot mess. His head was haphazardly bandaged beneath his hat barrette, he had huge bags under his eyes from nightmares involving Mabel, and though he'd showered, the blood stains hadn't come out of his clothes.

Things were getting out of and. He was afraid to eat, afraid to sleep, and terrified in the moments he thought Mabel was looking away long enough for him to bother Dipper. He had to keep reminding himself that he was an immortal being of pure energy, much more powerful than a mere mortal. At the present, he didn't feel like a being of pure energy- in fact, eh felt more drained than he ever had. If death was a feeling he was pretty sure this was as close as you could get without actually feeling it. His skin was pale and clammy. His ribs were beginning to show. He gnawed at the dry skin on his lips and nervously toyed with his hat barrette. Every time he thought he saw Mabel it felt like he was falling out of his chair. Pure, unadulterated fear shot through him every time he saw her sweater. He felt sick.

"I've got to get the upper hand," he muttered to himself in English.

Lana sat next to him.

"What'd you say?" She demanded.

"Nothing! Leave me alone." He snorted, then added under is breath, "You bloody monster."

"I heard that, Cipher. You're doomed the instant class is over."

Great. Now he'd have to worry about Mabel _and_ Lana.

The after class beating was fairly light. Nothing out of the ordinary until he caught an unusual insult-

"Take that, you triangle piece of shit!"

"I'm human!" He wailed as he was kicked in the ribs, "How could you possibly-"

A bit of red hair slipped out from under a wig. The jig was up.

" _Lumberjack girl?_ "

Wendy pulled the wig off. "You bet your pathetic, sniveling ass it's me. I couldn't just abandon those poor, defenseless little cinnamon rolls to your devices. I saw you get on the bus with them."

"How?"

"Lumberjacks murder trees every day. When you kill that many things, you begin to see demons."

"What the absolute fuck is wrong with you? That's not how trees work!"

"Shut up. I do what I want."

Wendy spat on Bill, then left to go tell Dipper and Mabel that she'd been Lana all along. If she didn't, Bill would probably just tell them anyway.


	6. Powerful Alliance Threatens Bill More

The twins had invited their friend over for dinner, and their folks had asked Wendy to babysit for the evening while they went to a party. They'd initially planned on having Bill watch them, but with his concussion, they couldn't turn down the opportunity when it walked through the door. They kissed Dipper and Mabel goodnight early, then left them at the table with Wendy. Bill had slunk off to bed.

"Wow, Wendy! I can't believe we didn't recognize you. I didn't know you were so good at volleyball, either!"

"I never told you because I feared you'd want to face off against me. I have murdered dozens with volleyballs."

"You've killed people playing volleyball?"

"Not people. Trees."

"You can cut through trees with a volleyball?"

"Not cut through. Smash through. I blow the base of the trunk into a pathetic bunch of toothpicks and the rest comes crashing down."

Dipper gulped. That sounded horrifying.

"What's been going on with you two lately? I bet living with Bill's been pretty miserable."

"Actually, it hasn't been that bad. He can't do very much in his human form." Dipper rubbed his chin. "He's been having pretty awful luck, too."

Wendy and Mabel locked eyes. Luck? Who needed luck. They grinned. Mabel would reveal all the things she'd been doing once Dipper was out of earshot.

"He doesn't seem to know how to take care of a human vessel," Dipper continued, "So he's always getting hurt and he doesn't shower or wash his clothes enough. It's really gross. I think I heard him cry himself to sleep the other night. I guess pain isn't so funny to him anymore now that he lives with it. Maybe he'll just go back to being a triangle in a while, you know? Leave us alone."

Mabel nodded. "That'd be nice. Then he wouldn't have to get hurt all the time. He could go back to having powers and living comfortably."

Bill's door was cracked, so she hoped he was listening in and would take a hint, but she couldn't be sure he hadn't just gone to bed.

Wendy glanced at the wall clock.

"Oh, man! It's almost ten. Time for you two to get ready for bed."

Dipper and Mabel hopped out of their seats.

"I'm gonna change into my PJ's," Mabel announced.

"I think I'll take a shower." Dipper headed down the hall.

Mabel immediately sat back down and scooted closer to Wendy.

"So, what's up, little dude?" Wendy asked excitedly.

"I set him on fire day one and he took the blame," Mabel explained giddily, "And I turned a whole store of people against him back to school shopping. And his concussion? The other night he thought he'd creep into our room while Dip and I were sleeping and touch Waddles!"

"Oh. My. God. What'd you do?" Wendy leaned in closer.

"I bashed him over the head with an old chair leg. Quebracho wood. I found it in the attic years ago- no idea where the rest of the chair is, but it's the best thing I've ever found for bludgeoning."

Wendy grinned. "That's some seriously hard wood! I be that hurt like Hell! Do you just keep it nearby?"

"It fits in the little space between my bed frame and the mattress. It's the perfect thing to keep on hand in case of burglars. Pretty sweet, huh?"

"Totally! Does Dipper know?"

"Nope. I don't want him to worry about me, so I've been trashing Bill on the sly. I think he must be close to breaking if he cried himself to sleep!"

"I'll help you all I can. Next week, we start the Volleyball unit. I'm gonna make him wish he was a being of pure energy again."

"I'll keep working on him at home."

They shook hands.

"This is gonna be great!"

"What's gonna be great?" Dipper stood in the hall in an old pair of pajamas with a towel on his head.

"Just a new art project Wendy and I plan on making," Mabel told him.

"Huh. Let me know how it turns out." He chuckled awkwardly. "Anyway, it's time for bed, Mabel. 'Night, Wendy."

"G'night, Dipper. Night, Mabel."

"Goodnight, Wendy."

The twins headed back down the hall. Mabel started through the crack in Bill's door and grinned wickedly.

' _Sweet dreams, demon._ '

Her powerful new alliance with Wendy was sure to drive Bill over the edge. She just had one question: How would he revert back to being pure energy? How could he rid himself of physical form? Was it just something demons could do? Man, what was taking him so long?


	7. Sweet Bootied Leviathan Bent Over a Tabl

"Alright, kids! Volleyball again today. Same teams. Lana, your team will be playing Bill's today."

The seniors had picked teams. Wendy, of course, chose Mabel. Dipper was, unfortunately, on Bill's team. The girls had hoped he wouldn't have to see this.

Yet, in spite of this, they grinned eagerly. They'd been waiting for this match all week.

"You're going down, Ciper!" Mabel called. Her and "Lana" would kick his ass. Mostly Lana.

"You wish!" Bill grabbed the ball. "My team gets first serve," he added menacingly.

He narrowed his eye. He knew that Wendy could probably send the ball back his way, but if he aimed for Mabel, he could probably either score a point or do some damage. Either worked for him.

He spiked the ball into the opposite court. Mabel hit it back, weaker than Bill knew she could if she were really trying. It barely went over the net. One of Bill's other players- a girl named Amelia- managed to send it back over before it hit the floor. Kyle, a boy on Wendy's team, sent it back.

Bill found his opportunity again and hit it toward Wendy while he thought she was distracted barking orders at her team. Unfortunately for him, Wendy didn't need o be looking at the ball to send it back to him. She punched it right through the net and into Bill's chest, knocking him over. Everyone heard the sickening crackling of three of his ribs shattering like Christmas ornaments being run over by a truck.

Bill had no idea mortals could endure such pain. Why the hell did they bother living as long as they did? This was terrible! Pain wasn't hilarious anymore! It was terrible!

Instinct kicked in and Bill started screaming, curled up in fetal position with tears running down his face and pooling on the floor. He could taste blood.

"Sweet bootied Leviathan bent over a table, what the Hell happened to Cipher?" Their teacher raced over.

"He got hit by a volleyball," Amelia explained.

"Who hit him?"

Everyone at once, still remembering that Bill had hit poor, sweet, precious Mabel with his bag the week before shrugged and muttered about not knowing.

"That thing must've been going faster than a jet plain in a hurry to do damage like this. These things aren't even hard- we can't afford to put enough air in them with our public school budget. Hoo, boy, it even went through the net. Whoever did this has a promising future as an Avenger ahead of them!"

Wendy hid her glee behind a straight face. Mabel just turned her head and tried to choke down laughs.

"Awe, Mabel, it's okay." One of her classmates soothed, mistaking her laughs for sobs, "I know you're worried about your guest, but I'm sure he'll be fine."

That classmate had to speak very, very loudly to be heard over Bill's never-ending shrieks of agony.

The ambulance arrived and paramedics carried Bill off on a gurney. Everyone watched him go, but nobody waved goodbye. The only thoughts going through people's heads were, "Serves him right," "Fuck that guy," or, "Oh cool almost time to go home I wonder what's in the fridge."

The janitors cleaned up his blood and tears and by the time they were done the kids changed out of their PE uniforms into their street clothes. Dipper was going a good job of keeping Wendy's secret and calling her Lana as needed at school. It was like a cool secret agent game to him.

Even more so for Mabel. Keep her partner in crime's secret safe. Keep her brother safe. Kick demon ass and rejoice in his tears and wails of pain.

That night, Bill was told it would take six weeks for his ribs to heal and that he'd have to stay home for that amount of time and rest.

Being a stupid ass demon, he stayed home for two weeks before dragging his injured ass out of bed and making the injury much worse when he "tripped" and fell down the school stairs, right in front of poor little Mabel.

She, of curse, rushed down.

"Oh, gosh, Bill! Are you okay?"

He was screaming too loud to hear her. Another trip to the emergency room, another diagnosis of a broken bone. This time, his left arm. Luckily enough, he was ambidextrous. He kept himself busy in his room doing homework or sobbing loudly into his meals before Dipper and Mabel's parents would gently remind him that doing such things wasn't good for his healing ribs. After that, he'd try to calm down enough to cry himself gently to sleep.


	8. Bill Strikes Back

"Oh, I just don't understand why Billy's not healing!" The twins listened to their mother in the kitchen. "He's been resting up, we've been feeding him well, and he hasn't been stressing his injuries, so why is he getting worse? And has he been looking thin to you?"

Their father grunted. "Yep, I'd say so. Do you think he needs a higher calorie diet?"

"Maybe. Or maybe he just doesn't like what I've been cooking- I should ask what his favorite food is. Maybe if I make it more often, he'll put some meat on his poor little bones!"

Mabel giggled to herself. She knew why Bill was so thin. He'd hardly eaten a thing since his injury. She and Wendy had casually slipped some false information to him by having a conversation and pretending not to know that he was listening in.

"Boy, I hope Bill keeps eating- he'll never get better if he keeps stuffing his face!"

"Yeah- Digestion will take so much energy, his wound will just get worse and worse. Who knows; maybe we'll get lucky and we'll just eat until he succumbs to infection!"

And so thus began his fast. He hadn't trusted food to begin with, anyway- at first, he thought it was some strange human ritual to cleans their bodies of sin. The sin would become a physical manifestation, coded "poop" and nobody ever really talked about it because they were ashamed of their sins. Well, Bill wanted to keep his sin. But then he had to eat because he needed to blend in. Then, he figured out that if he used food for it's better use- crying into it and then flushing it down the toilet so it looked like he was eating- things went much more smoothly.

Now, he was bony, pale, unwashed, emaciated, stuck hobbling around because he refused a wheelchair (who sits on anything with wheels? too suspicious and human for him!), and his wounds were getting worse. He was in a miserable mood all the time- Mabel doubted he'd last much longer.

"Mom! Dad! We're leaving for the bus stop now!"

Their parents stopped fretting for a moment.

"Oh- yes. Goodbye, kids! Have a good day at school!"

"We love you, kids!"

The twins stepped outside and found Bill hunched over on the porch swing, panting heavily. Moving with broken ribs exhausted him.

"You want some help getting to the bus stop?" Mabel offered sweetly.

"Piss of, I'll walk myself!" Bill swatted her hand away, wincing at the pain it caused him. "Stupid kid..." He muttered.

Mabel shrugged, watching him stagger up the street in front of them. Her and Dipper had adjusted to scraping him off the sidewalk whenever he fell.

A few people stood waiting for the bus, making small talk with their friends, but for the most part people kept quiet and just stared up the street. The bus was running late.

"Sooo...How're your ribs doing?" Dipper asked, trying to break the awkwardness.

"Fine," Bill hissed, clutching his sides.

The bus was approaching.

"Are you sure? It looks like you're in pain. It's been a few weeks- aren't your broken ribs feeling any better?"

Bill saw his opportunity. He seized Dipper's arm. "You tell me when you're this far along in the healing process!" The demon shoved Dipper into the street, right in to oncoming traffic.

"Dipper!"

Mabel leaped into the road and grabbed her brother, looking up just in time to see the bumper and shield him with her shoulder.

The two children sailed through the air for a couple feet, Mabel keeping a surprisingly good hold on Dipper and managing to keep him on top so she took the worst impact from the street. It tore right through part of her sweater, ripping open her back and leaving an agonizing road rash. Her shoulder screamed where the ca had hit her. The collision hadn't been high-speed, but it was enough to do some damage. Mabel wasn't crying crocodile tears this time.

"Oh my gosh- Mabel!" Dipper dragged his twin back to the sidewalk. Traffic stopped and the driver of the vehicle frantically checked on Mabel as he called an ambulance.

"I'm so sorry- I didn't even see you two until it was too late!"

"It's not your fault," Mabel whimpered, giving Bill the evil eye through her tears. She was going to be out of commission for a while. She had to contact Wendy.

The ambulance drove them to the hospital, where their parents waited impatiently to check on their babies.

"Oh, thank goodness you're safe! How did this happen? Why were both of you in the street?"

"Bill pushed me!" Dipper told them, waving his arms frantically, "He pushed me in the street and Mabel jumped in front to protect me."

Their mother covered her mouth. "Oh, Dipper, that's a terrible accusation. Are you sure he pushed you? He didn't just bump in to you?"

"Yes!"

"It had to have been and accident. I need to hear Bill's side."

"WHAT?!"

"Just let it go, Dipper," Mabel told him through grit teeth, "Ask Wendy if she can babysit me tomorrow."

Dipper nodded. "Do you want me to stay home, too? I don't need to go to the DDMD club meeting."

"No, no- not unless you're hurt, too."

"The doctor said it was just a few scrapes." Dipper looked down guiltily. "I'm sorry, Mabel."

"Don't worry about it, Bro-bro. I was the one who jumped into the street. It's not your fault."

Her brother nodded, but his eyes betrayed him. He still felt responsible somehow.

Mabel hoped he'd perk up soon- she wanted him to be in a light mood to enjoy the revenge she was plotting against Bill for this. Trying to hurt Dipper was the last straw. Bill had sealed his own fate- Mabel and Wendy were going to obliterate every shred of hope Bill had. Grind it to dust, throw it in his eye, and then spit on the dust.

Bill didn't know the true meaning of Hell. Not yet. Mabel had plans to fix that.


	9. Doom to the Geometric Douche Bag

**Author's note: I meant to post that chapter weeks ago. I forgot I hadn't- sorry about that.**

 **Also I forgot I was writing this. Oopse. On the bright side, here's the finale.**

 **TRIGGER WARNINGS: Violence, gore, swearing, suicide**

* * *

Mabel was in bed. She and Dipper had traded bunks- she slept on the bottom now so she wouldn't have to climb down a ladder. Wendy sat next to her in a chair, seething with rage.

"Dude, he pushed you into traffic. I'm going to murder his ass."

Mabel shook her head, wincing a little. She needed to hold still until her road rash healed.

"No. We need to make it look like the blood is on his own hands. We need to bring out the big guns while he's still weak. His ribs and arm aren't healing. Tomorrow at school, talk to everyone. Tell them how he pushed me. Make it sound like I'm in terrible condition."

"You are in terrible condition. You can barely move!"

"Good. Tell them about me. Remind everyone it also ruined a perfectly good sweater that I spent HOURS on."

Wendy's phone vibrated and she paused to look at it.

"No. Way."

"What?"

"Tambry just sent me a video of you saving Dipper from the car. Ouch. It's even got Bill pushing Dipper."

"Good! This is perfect! Show that to _everybody._ "

"The whole school already hates him- now things are gonna get serious."

The two snickered. This plan was beautiful.

"Tell me how it goes tomorrow, okay?"

"You know it, Mabel. For now, though, get some rest. You've got healing to do. Leave this to me for now."

"Thanks, Wendy. You're the best."

The next day at school put Bill at a new low. Wendy forwarded the video to everyone she knew with instructions to keep it moving. The whole school anted to beat the shit out of Bill. His entire day was a chorus of, "Hey, Cipher- after school you're dead meat, you hear?" and, "Hope you like the feeling of broken bones, Bill, because I'm going to give you the worst compound fracture of your life!"

Worse still, he was constantly being pelted in spitballs, stuck with pencils, hit with water bottles full of what could only be apple juice or pee, shoved in the hallway, slammed in doors, pushed on stairs, slapped between classes, kicked in the shins, and being sprayed in the face with Axe Body Spray.

After school, several people made good on their promise to kick his ass when they dragged him out behind the gym and took turns hitting and kicking him. He wasn't sure there was a centimeter left on his body without a bruise.

Dipper had been telling people things, too, about how amazing Mabel was to save him and about her injuries and reminding them of how good she was in general, which only fueled peoples' hate for Bill.

Weeks of agony went on for Bill. Every time he thought people were getting over it, the video would resurface, or Dipper would bring a new story about what Mabel had done that day, or Wendy would call him a Miserable Mabel Mauler and everything would start back up again. Mabel had not taken matters to the police, and when she returned to school, she was told over and over how good of her that was.

Bill was stuck slinking around avoiding as many beatings as possible on a daily basis. Then, one day, the worst experience of his life drove him over the edge.

Wendy Corduroy grabbed him by the back of the neck in the cafeteria, rolled up her jeans to the knee, and rubbed her hairy leg on his face, focusing mainly on his eyes. He screeched for mercy and begged for help, but to no avail. She rubbed his eyelids raw and pieces of his eyebrows were worn off. When she was finally satisfied, she shoved him down on the floor, grabbed a box out of her pocket, and tipped it over, dumping a variety of spiders on his head.

That was the last straw for Bill. He was sick of being in pain. Sick of being tormented. Sick of being mortal. He wanted to be his old self again- the one that felt no pain, the one that did the tormenting, the one that knew for sure he had a promising future ahead of him instead of another day of getting his ass kicked.

"THAT'S IT!" He cried, trying to brush the spiders off as they bit his face, "I'M DONE BEING MORTAL!"

He raced outside. A mass exodus took place from the cafeteria as everyone ran outside to see what Bill was up to. He climbed up to the top of the school roof and stood.

"Behold, mortals- I'm about to show you my true form!"

He leaped down, crushing the last bit of his mortal body's endurance, and emerged in his familiar triangle shape, cackling.

"Wait, Bill is a triangle?"

"He always seemed pretty fuckin' square to me!"

"Wow. He's even uglier as a demon. Nice hat, you geometric douche bag!"

Bill narrowed his eye.

"Silence!"

He hovered down to his physical body and ate it through his eye-mouth. It was kinda weird, even for him, so he did so rather uncomfortably. He tried to hurry because he could feel people watching. Physical bodies took a lot of energy, okay?

Mabel grinned. "Now, Wendy!"

Wendy rolled up her other pant leg. Her leg hair began vibrating angrily, and an unearthly hum split the air. They were angry.

"Sick 'em!"

Wendy's leg hairs popped off and charged Bill, surrounding him and eventually engulfing him. He screamed. How could this be possible? He was a being of pure energy.

"You see, my leg hairs feed on demons, Bill. I've hated you all along. I knew something was off when they stopped whining for food back in Gravity Falls, so I tracked you here. Now, you're done for. Nothing can quell their thirst for demonic blood."

Bill's death was barbaric and hard to watch, but people couldn't peel their eyes away as he was consumed into nothingness.

The principal took a sip of coffee.

"Well would you look at that Billy got into another fight. Guess we have to expel him."

Everyone cheered. Fuck that triangular menace. Wendy and Mabel were hoisted up on their peers' shoulders.

"Hooray for Mabel and Lana!" they cried.

"My name is Wendy- Wendy Corduroy!"

"Hooray for Mabel and Wendy! They got that sinful being outta here!"

 **FIN**


End file.
